Use of fumagillol and derivatives thereof for preparing medicaments against intestinal infections

ABSTRACT

The invention relates to the use of fumagillol and the esters formed by fumagillol and saturated or unsaturated (C 1  -C 12 ) alkylcarboxylic or (C 1  -C 12 ) alkyldicarboxylic acids, and their pharmaceutically acceptable salts, for the preparation of medicaments for combating intestinal infections caused by microsporidia and/or cryptosporidia.

The present invention relates to a novel use of fumagillol and itsderivatives, especially fimagillin.

Fumagillin is an antibiotic, first described in 1951 (The Merck Index11th Edition, no. 4199), which is used especially for preventing orcontrolling parasitic diseases in fish farming and beekeeping and whichhas also been used in man for the local treatment, in an eye lotion, ofkeratoconjunctivitis due to Encephalitozoon hellem (J. Ophtal., 1993,115, 293). However, it has been found to be inactive as a carcinolyticagent (Antibiotic Annual, 1958-1959, 541-546).

It has now been found that fumagillol and certain esters formed withthis compound, when formulated in a drug, especially an oral drug, arecapable of resolving very serious infectious conditions of the intestinedue to microsporidia or cryptosporidia.

It has also been found, surprisingly, that fuimagillol and the estersformed by fumagillol and saturated or unsaturated (C₁ -C₁₂)alkylcarboxylic or (C₁ -C₁₂) alkyldicarboxylic acids are capable ofinducing eradication of Enterocytozoon bieneusi in patients affected byHIV. This discovery is surprising and decisive because there iscurrently no known remedy for this type of infection, which constitutes95% of the intestinal infections due to microsporidia which result incachexia and death in patients suffering from AIDS.

Thus, according to one of its features, the present invention relates tothe use of fumagillol or esters formed by fuimagillol and saturated orunsaturated (C₁ -C₁₂) alkylcarboxylic or (C₁ -C₁₂) alkyldicarboxylicacids, and their pharmaceutically acceptable salts, for the preparationof drugs for combating intestinal infections due to microsporidia and/orcryptosporidia.

More particularly and advantageously, according to its preferredfeature, the present invention relates to the use of fumagillol oresters formed by fumagillol and saturated or unsaturated (C₁ -C₁₂)alkylcarboxylic or (C₁ -C₁₂) alkyldicarboxylic acids, and theirpharmaceutically acceptable salts, for the preparation of drugs forcombating intestinal infections for which the parasite Enterocytozoonbieneusi is principally responsible.

"Saturated or unsaturated (C₁ -C₁₂) alkylcarboxylic or (C₁ -C₁₂)alkyldicarboxylic acids" are understood as meaning carboxylic ordicarboxylic acids of linear or branched alkyls, it being possible forsaid alkyls to contain one or more double bonds.

Examples of such acids are acetic, propionic, butyric, valeric, pivalic,malonic, succinic, acrylic, crotonic, isocrotonic, oleic, maleic,fumaric and 2,4,6,8-decatetraenedioic acids.

The ester of fumagillol and 2,4,6,8-decatetraenedioic acid, fumagillin,is a particularly advantageous compound.

The esters of the present invention are easily prepared by reactingfumagillol with the appropriate acid under the normal esterificationconditions described in the literature.

Fumagillol, either as such or esterified with a (C₁ -C₁₂)alkylcarboxylic or (C₁ -C₁₂) alkyldicarboxylic acid, can be administeredin the form of the free acid or else in the form of one of its saltswith a pharmaceutically acceptable base.

For their administration to patients suffering from an infection due tomicrosporidia or cryptosporidia, fumagillol or the esters formedtherewith are mixed with pharmaceutical excipients commonly used for thepreparation of pharmaceutical formulations, preferably for oraladministration.

Advantageously, the compounds of the present invention are formulated asactive principles in dosage units, for example tablets or gelatincapsules, containing from 1 to 200 mg of active principle,advantageously from 2 to 100 mg, more advantageously from 5 to 50 mg orpreferably from 7.5 to 30 mg per dosage unit.

The pharmaceutical compositions for oral administration constitute afurther subject of the present invention.

In the pharmaceutical compositions of the present invention for oraladministration, the active principle can be administered in theabove-mentioned unit forms of administration, mixed with conventionalpharmaceutical carriers, for the treatment of the above-mentioneddiseases. The appropriate unit forms of administration include oralforms such as tablets, which may be scored, gelatin capsules, powders,granules and solutions or suspensions to be taken orally.

When a solid composition is prepared in the form of tablets, which isone of the preferred forms, the main active ingredient is mixed with apharmaceutical vehicle such as gelatin, starch, lactose, magnesiumstearate, talcum, gum arabic or the like. The tablets can be coated withsucrose or other appropriate substances or else they can be treated soas to have a prolonged or delayed activity and so as to release apredetermined amount of active principle continuously. These delayedaction or controlled release tablets represent another very advantageousform.

A preparation in the form of gelatin capsules, which is anotherparticularly advantageous form, is obtained by mixing the activeingredient with a diluent and pouring the resulting mixture into soft orhard gelatin capsules.

A preparation in the form of a syrup or elixir can contain the activeingredient together with a sweetener, which is preferably calorie-free,methylparaben and propylparaben as antiseptics, as well as a flavoringand an appropriate color.

The water-dispersible granules or powders can contain the activeingredient mixed with dispersants or wetting agents or with suspendingagents such as polyvinylpyrrolidone, as well as with sweeteners or tastecorrectors.

The active principle can also be formulated as microcapsules, optionallywith one or more carriers or additives.

In the pharmaceutical compositions according to the present invention,the active principle can also be in the form of an inclusion complex incyclodextrins, their ethers or their esters.

Pharmaceutical compositions for oral administration, containing from 1to 200 mg, preferably from 2 to 100 mg, from 5 to 50 mg or from 7.5 to30 mg, of fumagillol, an ester formed by fumagillol and one of the acidsmentioned above, especially fimagillin, or one of their pharmaceuticallyacceptable salts as the active principle, in a form selected fromtablets, delayed action tablets, controlled release tablets and gelatincapsules, constitute a further subject of the present invention.

The compounds of the present invention can be administered with otherdrugs generally used during the development of AIDS, and can also beformulated in association with other antiparasitics or antibiotics orwith drugs having an anti-HIV action.

The therapeutic activity of the compounds of the present invention wasdemonstrated by administering different doses of the pharmaceuticalcomposition of Example I to four homosexual patients of the male sexpresenting a high immune deficiency with an average CD4 level of 66(11-158). Three patients had recognized AIDS and one patient had an ARC(Aids Related Complex). The average age was 40 years.

Prior to inclusion, all these patients had consecutive stoolexaminations which were positive for microsporidia. Two patientsconcomitantly presented an intestinal infection with cryptosporidia. Thetest for microsporidia in the urine remained negative in all thepatients, these factors favoring the diagnosis of infection withEnterocytozoon bieneusi.

All the patients had a duodenal fibroscopy with biopsies. In threepatients, microsporidia were identified on these biopsies in histologyand in direct parasitology, as well as by electron microscopy. In thefourth case, only electron microscopy revealed the presence ofEnterocytozoon bieneusi.

The four patients received 20 mg of fumagillin three times a day, i.e.60 mg/d, for 21 days.

Eradication of the parasite from the stool was observed in all thepatients in the control examinations after 15, 17 and 21 days oftreatment. Microsporidia were still absent from the patients' stool onemonth after cessation of the treatment.

Of the two patients who presented cryptosporidia in their stool prior toinclusion, only one transitorily tested negative on his stool,cryptosporidia reappearing one month after cessation of the treatment.

All the patients had a control duodenal fibroscopy to assess thedisappearance of the parasites at tissue level. Also, in two cases, anegative result was observed in histology, with the persistence of veryrare microsporidia in direct parasitology (probably cadavers ofmicrosporidia). The electron microscopy study confirmed the totaldisappearance of Enterocytozoon bieneusi in all four patients.

Another group of patients was recruited for a tolerance/toxicologystudy. Doses of 10, 20, 40 and 60 mg of fumagillin were administered totwenty-four patients (six per dose level).

The treatment was tolerated well. In particular, no hepatic toxicity,cardiac toxicity (ECG) or renal toxicity (creatininemia) was observed.Even a very slight decrease in the serum alkaline phosphatase level wasnoted, which could correspond to a beneficial effect of the treatment oncholangitis due to microsporidia.

The troublesome side effect observed was of the hematological type,namely thrombopenia which varied in degree but was never very severe(except in one case which caused the administration to be interrupted inthe above group of four patients) and whose evolution was spontaneouslyregressive in 10 to 14 days after cessation of the treatment. This sideeffect, which is not immunological but due solely to a direct toxicitytowards the platelets, can be corrected by an appropriate choice oftreatment protocol.

In conclusion, eradication of the parasite from the stool was observedfor the first time in this opportunistic infection; this eradicationpersists for at least one month after cessation of the treatment andseems to be accompanied by eradication of the parasite from the duodenalbiopsies. This result has never been achieved with other antiparasitics.

The clinical benefit is difficult to evaluate in these patients in viewof the multiple associated infections and the pursuance of symptomatictreatments. A very marked clinical benefit was nevertheless obtained inthe patients treated, who all gained several kilograms and whosediarrhea stopped at the end of the treatment.

Consequently, spectacular parasitological results were obtained withfumagillin in Enterocytozoon bieneusi infections in the course of AIDS,with an excellent clinical result in some cases.

EXAMPLE 1

Pharmaceutical composition in the form of gelatin capsules eachcontaining 20 mg of fumagillin acid

14 g of purified and pre-sieved fumagillin acid are gradually diluted toa volume of 210 ml with the requisite amount of colloidal silica(AEROSIL®). The powder obtained is mixed thoroughly and the homogeneouspowder prepared in this way is divided up into no. 3 opaque hard gelatincapsules. This gives 700 gelatin capsules each containing 20 mg offlimagillin acid.

We claim:
 1. A method of treating intestinal infections due tomicrosporidia and/or cryptosporidia which comprises orally administeringto a subject in need thereof an effective amount of fumagillol, an esterformed by fumagillol and a saturated or unsaturated (C₁ -C₁₂)alkylcarboxylic or (C₁ -C₁₂) alkyldicarboxylic acid, or apharmaceutically acceptable salt thereof.
 2. A method according to claim1 wherein said ester is fumagillin.
 3. A method according to claim 1 fortreating intestinal infections for which the parasite Enterocytozoonbieneusi is principally responsible.
 4. A method according to claim 3wherein said ester is fumagillin.
 5. A method according to claim 1wherein oral administration is effected by means of tablets, gelatincapsules or delayed action or controlled release tablets.
 6. A methodaccording to claim 2 wherein oral administration is effected by means oftablets, gelatin capsules or delayed action or controlled releasetablets.
 7. A method according to claim 3 wherein oral administration iseffected by means of tablets, gelatin capsules or delayed action orcontrolled release tablets.
 8. A method according to claim 4 whereinoral administration is effected by means of tablets, gelatin capsules ordelayed action or controlled release tablets.
 9. A method according toclaim 5, wherein said effective amount is in the range 1-200 mg.
 10. Amethod according to claim 6, wherein said effective amount is in therange 1-200 mg.
 11. A method according to claim 7, wherein saideffective amount is in the range 1-200 mg.
 12. A method according toclaim 8, wherein said effective amount is in the range 1-200 mg.